PROBLEM TO BE SOLVED: To provide a radiation detector that is improved in reliability associated with radiation detection.SOLUTION: A radiation detector 1 according to the present invention includes a support substrate 2 through which radiation is transmitted； a scintillator layer 3 which has an incidence surface 3a that the radiation is made incident on and an emission surface 3b emitting light generated by the incidence of the radiation on the opposite side from the incidence surface 3a, and is formed on one principal surface 2a of the support substrate 2； and an optical detection part 5 which is arranged on the side of the emission surface 3b of the scintillator layer 3, and detects the light emitted from the emission surface 3b. A side face 3c of the scintillator layer 3 tilts outward from the side of the incidence surface 3a to the side of the emission surface 3b, and the support substrate 2 has an outer edge part 2b reaching the side face 3c of the scintillator layer 3.【課題】放射線検出に係る信頼性の向上を図ることができる放射線検出器を提供する。【解決手段】本発明に係る放射線検出器１は、放射線を透過させる支持基板２と、放射線が入射する入射面３ａと入射面３ａの反対側で放射線の入射により生じた光を出射する出射面３ｂとを有し、支持基板２の一方の主面２ａに形成されたシンチレータ層３と、シンチレータ層３の出射面３ｂ側に配置され、出射面３ｂから出射された光を検出する光検出部５と、を備え、シンチレータ層３の側面３ｃは、入射面３ａ側から出射面３ｂ側に向かうほど外側に傾斜し、支持基板２は、シンチレータ層３の側面３ｃに至る外縁部２ｂを有する【選択図】図１
